Published reports of underground mining advances in the Arizona Copper Company Mines near Clifton, Arizona. Written reports, a letter of inquiry, and a schematic of the smelter; black and white images.

258 pages (PDF version). File size: 778.356 KB. Discusses how Phoenix is meeting the federal Clean Air Act's 15 percent rate of progress plan for air pollution. Includes statistics on Phoenix area air pollution in the 1990s, rate of emission for...